Nozzle for the production of artificial filaments



Patented July 10, 1928.

UNITED; STATES .PATENT OFFICE.

LEONARD ANGELO LEYY, F CRICKLEWOOD, ENGLAND;

NOZZLE FOR THE PRODUCTION OF ARTIFICIAL FIIJAMENTS.

No Drawing. Application filed August 16, 19%, Serial lilo. 129,660, and in. Great Britain September 14%,

This invention relates to improvements in connection with nozzles for the production of artificial filaments. I V

In the production of artificial filaments,

especially in processes wherein a fine filament is extruded at high pressure, it is necessary to provide very fine, strong uniform orifices through which the material is forced.

To obtain efiicicnt results, such orifices must comply with certain conditions. For example, they mustbe of uniform diameter they must offer uniformity of resistance to the flow of the extruded material, and they must Withstand wear.

The material which best conforms to these requirements is glass, which is preferable to metal, from which latter. material it is very diflicult to make orifices of very fine diam- 20 eter through more than a very small thickness. In addition the wear on glass is con-. siderably less and it causes less frictional resistance to the flow of the extruded material.

A known method of making such orifices is to select carefully by means of microscopic examination, glass capillary tubing of exactly the diameter required, which may be, say, 0.1 or 0.08 1n;m. and to seal to asmall portion of such capillary tubing a piece of tube of somewhat larger diameter, to provide the lead-up for the attachment of the jets to the nozzle-heads.

It is obvious that the flow from such nozzles will. vary' according to the length '&5 of the capillary tubing and to the exact shape of the capillary lead-up i. e. that portion. of the capillary which is enlarged for attachment to the wider glass.

Now, according to my invention in order that the jets shall interpose exactly the same 4 resistance to the fiow of the extruded material, I force water, oil, or other suitable liquid under considerable pressure through the nozzles which have increasing bores, whilst they are being ground down across 46 the openings by means of a carborundum or suitable grinding stone. Measurements of the total flow in a given time at intervals are made and the grinding is continued until the flow in a given interval through the jet 5 reaches a definite fixed value. I have found that the most efficient means of holding these jets during the grinding operation, is by hand, and while any suitable means of measuring may be employed for ascertaining the rate of flowof water or oil when dotermining the jet size, I prefer to measure the quantities passed in a given time by removing the jet from the stone at predetermined intervals, and collecting the liquid in a Burette. By these means all the jets are made of exactly the same flow value and inaddition there is no liability ofthe capillarybore being stopped up grinding. 4

Claim: 1

The method of determining the varying diameter of a tapered orifice, in a nozzle being ground, which consists in passmg a fluid through said Orifice under a predetermined pressure, and measuring the quantity of said fluid passed therethrough in a given time at predetermined intervals.

LEONARD ANGELO LEVY.

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